Bats already are struggling to survive in the Upper Peninsula.

White-nose syndrome — so named for the frost-like fungus that bats with the disease develop around their nostrils — has so decimated populations at their wintering sites that some area caves where numbers had been 20,000 or more now are down to a few thousand, experts with the Michigan Department of Natural Resources say.

White-nose syndrome can disrupt a bat’s hibernation, waking them early and causing them to burn up energy needed to get through the winter. Bats will fly out while snow still covers the ground in a vain search for food, or succumb to hunger and cold in the cave.

It’s been devastating to bats in at least 29 states and six Canadian provinces, to the point of considering the little brown bat, the big brown bat and, in particular, the northern long-eared bat for federal protection.

So, given the bats’ dire situation, it’s been disappointing to see vandals target not one but two known local sites where the bats are known to dwell.

The most recent is graffiti on the Millie Hill educational signs, many of them detailing the resident bat population and the important role they play as insect eaters.

The March incident at a cave on private property in Norway was more serious — individuals broke a metal gate, stole signs and monitoring cameras and lit a bonfire, likely roused the hibernating bats. Worse, they compromised a research project in the cave on a possible compound to combat white-nose syndrome, DNR officials said.

It’s difficult to understand what might prompt these acts. But it’s safe to say the bats themselves did nothing to warrant being hit twice within a six-month span.

The bats, for now, are barely hanging on without someone giving them a further push over the edge toward extinction.

Even if you don’t have much sympathy for the bats’ plight, consider this — cruelty to animals often is an early warning sign of future abuse to humans.

If you have any knowledge of who did the vandalism at the Norway cave, it’s in everyone’s best interests to pass that information along to the DNR’s Report All Poaching hotline by calling or texting 1-800-292-7800.

If you have a tip about the Millie Hill damage, contact the Iron Mountain Police Department at 906-774-1234.